Spark plug



J. G. DICKSON.

SPARK PLUG,

APPLICATION FILED JULY 3|1919.

1,414,806 I Patented. May 2, 11922.,

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UNITED STATES PATENT omce;

- JAMES G. ZDICKSON, OF CHICAGO, ILLINOIS, ASSIGNOR OE ONE-THIRD TO WALTER IF,

. WOLF, OF CHICAGO, ILLINOIS. i

srnnx mm.

aligned multiple spark gaps are provided at the inner end of the s arking plug, with a resulting increased e cieney in the explosion roducing action of the same, all as will herelnafter more fully appear.

In the accompanying drawing:

Fig. 1, is a perspective View of a spark plug constructed in accordance with the present invention.

Figs. 2 and 3 are fragmentary detail sections of the inner end of the spark plug,

taken in planes atright-angle relation to each other.

Like reference numerals indicate like parts in-the several views.

Referring to the drawing, 1 designates the usual metal shell or bushing of the spark plug having an externally screwthreaded lower annular sleeve portion 2 adapted for engagement in the spark lug opening of an engine cylinder, and wit aninternally screw-threaded upper portion 3 adapted to receive a sleeve nut 4 by which the usual central core or plug 5 of insulating material, isjsecured in place.

6 designates the usual conductor arranged axially in the insulating core 5 and provided at its upper end with the usual binding post and nut 7 for connection with the line wire by which electro-motive force is supplied to Specification of Letters Patent.

Patented May 2, 1922.

Application filed July 3, 1919. Serial No; 308,589.

10 designates a bridge plate of insulating material attached to the lower surface of I the lower sleeve portion 2 of the main shell or bushing 1, between the respective terminal polnts or stems 8 and 9 above described, and preferably by means of a pair of depending saddle posts 11 as shown.

12 designates an intermediate block or stem of metal or' like conductive material, secured in a horizontally adjustable manner in the bridge plate 10 aforesaid, by attaching nuts'13, with its respective ends havin spaced relation to the respective termina points or portions 8 and 9 above described, and so that the electric current will make a primary spark in its jump between the supply terminal 8 and said block 12, and make.

a secondary spark in its jump from said block 12 to the return terminal 9. Such multiple spark production in an approximately straight line, and at the lower end of the spark plug wholly within the explosive mixture of the engine cylinder, is adapted to produce a certain and powerful explosion of said mixture.

Having thus fully described my said invention what I claim as new and desire to secure by Letters Patent, is

1. In a spark plug having supply and return terminals at its lower end, the combination of a transversely extending bridge plate of insulating material secured to the lower end of the spark plug bya pair of depending and diametrically opposed saddle posts, and a conducting block carried by such bridge plate in spaced relation to the aforesaid supply and return terminals.

2. In a spark plug having supply and return terminals at its lower end, the combination of a transversely extending bridge plate of insulating material secured to the lower end of the spark plug by a pair of depending and diametrically opposed saddle posts, and a conducting block secured in a horizontally adjustable manner to said bridge plate in spaced relation to the aforesaid supply and return terminals, and adjusting nuts at opposite sides of the bridge plate for efi'ecting the adjustment aforesaid.

Signed at Chicago, Illinois, this 21st day of June, 1919.'

JAMES G. DICKSON. v 

